1. Field of the Invention
This invention relates generally to inflatable-type modular occupant restraint systems for passenger vehicles or, as they are more commonly known, air bag restraint systems. More particularly, this invention relates to an improved means for quickly securing a passenger-side inflator in an air bag canister.
2. Description of Related Art
An air bag restraint system typically includes a canister, which has an open side and which canister encloses an inflator and at least part of an air bag, and a cover which conceals the module from view. A driver side air bag module is typically mounted in the center of the steering wheel behind a protective cover. When the air bag module is designed for the passenger side of a vehicle, the container may be located just behind the vehicle dashboard, cosmetic cover, or passenger side instrument panel (hereinafter referred to as "dashboard") and the cover may form an integral part of the vehicle dashboard.
When the vehicle is involved in a collision, a crash signal initiates operation of the inflator to cause the air bag to deploy. The inflator provides an inert gas (e.g., nitrogen) which is directed under pressure into the air bag to force the air bag out of the canister incorporated in the module and into the passenger compartment of the vehicle. As the air bag is forced out of the module, the pressure exerted on the driver-side protective cover or dashboard causes selected portions of the cosmetic cover to separate, in a predetermined manner, along tear seams or breakaway seams (hereinafter referred to as "tear seams") to enable the air bag to be directed into the passenger compartment.
In the conventional mounting of a passenger-side air bag inflator in a canister, as shown generally at 10 in FIG. 1, an inflator 12 having a first end 14 is inserted through opening 16 in the canister first wall 18. A mounting stud 20 attached to the first end 14 is inserted through a first aperture 22 in the canister second wall 24 and the inflator is secured with nut 26. A flange 28 on the inflator second end 30 engages with the opening 16.
As inflator designs improve, one modification is to remove the flange 28 on the inflator second end 30 to produce an inflator having a constant diameter. The aforementioned installation procedure and components must be modified to provide for the use of the improved inflator designs. Further, the aforementioned installation process requires a number of fastening steps and machine steps to secure the inflator, which installation steps increase the cycle time for the manufacture of a module. Further, the use of fasteners to attach the inflator to an air bag module is a major cause of reworking of the inflator module assembly due to the necessity of replacing broken or unsecured fasteners. Reworking of the inflator module is not always possible. In these situations the defective modules must be discarded, resulting in lost production and increased manufacturing costs. The elimination of fasteners in the manufacture of the air bag module assembly would eliminate a major cause for reworking and disposal of defective inflator modules. Further, a simplified attachment system which would permit easy removal of the inflator without the need for special tools would reduce the cost and time associated with reworking of the module should removal become necessary.
Paquette et al., U.S. Pat. No. 5,058,919, recites the use of an air bag/cover subassembly and an inflator/reaction device subassembly which combine to form an air bag module. The inflator/reaction device utilizes an end wall with a generally circular shape and a circular opening connected to the perimeter of the side wall by a slot. The opposite endwall is generally perpendicular to the side walls of the canister and has an opening to accommodate an inflator shaft and a resilient tab that deflects to permit the installation of the inflator then snapping back in place capturing the inflator shaft in the opening.
Webber, U.S. Pat. No. 5,234,227, recites an air bag assembly designed for installation in a variety of differently-configured passenger vehicle instrument panels. The canister of the Webber air bag assembly has two oppositely facing end walls. One of the end walls contains an engaging tab that is deflected by a lug attached to the end of the inflator when the inflator is installed in the canister. The engaging tab bites into the surface of the lug securing the inflator against removal.
The recitations of cited related art do not provide for positive engagement of the inflator to prevent the inflator from rattling within the canister due to vibrations caused by the operation of the vehicle. Further, the cited related art does not provide for easy removal of the inflator from the canister after the inflator has been installed.